Mine chain breaker



R. TEMPLE MINE CHAIN BREAKER July 30, 1957 3- Sheets-Sheet 1 Filed Oct. 30, 1942 3 iii July 30, 1957 R. TEMPLE 2,800,868

MINE CHAIN BREAKER Filed on. so, 1942 s Sheets-Sheet 2 INVENTOR. mag/W BY ,/u r ufr w WITNEJJE-S & yd. WM: 4 ,qrroe/v'frr.

July 30, 1957 R. TEMPLE MINE CHAIN BREAKER Filed Oct. 30, 1942 3 Sheets-Sheet 3 24 I I I I 2.7

I 5 a w w ENTOR. 29 BY M M m, flfl W Y 4,34 KITTOPNEYJ.

MINE CHAIN BREAKE Robert Temple, Pittsburgh, Pa., assignor to Temple Velocity Equipment, Inc., Wilmington, Del., :1 corporation of Delaware Application October 30, 1942, Serial No. 46,5590? 17 Claims. (Cl. 114221) This invention relates to underwater devicesfor severing the lines by which explosive mines are. anchored in oceans and other bodies of water. v

In my copending application Serial No'. 425,027, filed December 31, 1941, and now Patent No. 2,420,987, I havedisclosed such a device for cutting mine:anchor ing cables- A great m ny o those cu e re now n us -and are operating very satisfactorily. However, they are not satisfactory for cutting case-hardened chains, espeeially if the links are large, in case lengths ofsuch chains are used-for anchoring mines. Instead, the cutting knife would merely clamp onto the chain and pull the mine along behind the mine sweeper. About the only thing that could be done in such acase would be toreleasethe sweep line from the ship because it would betoo dangeous to try to disconnectthe cutter from the .chain. As

a t, e ep. in nd. l e when at ach d to.

'set off accidentally outside of the watet which does not obstruct the sweep line afterv it has severed a mine line, which is relatively simple inconstrnction, and which can be used over and over again withoutv returning i t ,to the manufacturer forreloading. I p

In o a e th. i emi9 ,mcvable. wedsei carried bya frame attached to the usual sweepline by which mine cable cutters aretowed throughthe water.

Near-the Operative nd o hewedsei e ramei provided with arecess forreceiving a link ofa chain [by which a mine is anchoredand which thesweep line has engaged and guided along to the frame. Therecess is shaped to holdthe link in a plane. substantially perpendicular to the direction of moyement of the wedge and centered relative thereto. When a chain enters the recess it actuates meansby which thewedge is driven between and against the ends of the two links connected to the opposite ends of the link caught in the recess. The force of the impact andthe wedging action forces the twoend links away from each other in opposite directions so that the center link is pulled apart or broken. It is not necessary that the wedge touch the center link. In case a cable instead of a chain is encountered by this device, the sharp end of the wedge cuts the cable against a support or anvil at theopposite, side of therecess. The device is thus effective with either cable or chains.

The wedge preferably is driven by the force of an explosion created when a firing pin sets ofl an exposive actuated accidentally it is operated by hydraulic pressure.

Thus, a passage in theframe communicates at one end charge behind the wedge. To prevent the pin from being '1 adjoining ends of the yokes.

2,800,868 Patented J ly 30, 1957 ice filled with water. Near the open end of thepassage there is a normally retracted spring-pressed plunger which is released when a mine line enters the severing recess. The released plunger exerts enough pressure on the water in the passage to cause it to move the firing pin and explode the charge. At about the same moment the, trigger that releases the plunger also preferably releasesa locking pin by which the frame is rigidly connected to a positioning member that compels the frame to project ahead of the sweep line as it travels through the water. When the charge has been exploded the device is of no further use until reloaded, so it is desirable to getit out of the way of any other mine line that might-engagethe sweep line and be obstructed by the frame. Therefore, whenthelocking pin is released, the frame rotates on-the sweep. line independently ofits positioning member and thus swings out of operative position toenable the next mine line to pass the device and be severed by v a similar device further along the sweep line.

The preferred embodiment of this invention, is:illustrigger; Fig. .6 is a fragmentary side view taken on the line (I -VI of Fig. 2; and Fig. 7 is, a fragmentary side view.taken on the line VII-VII of Fig. 2 and showing-a mine-anchoring chain in position for breaking.

Referring to Fig. 2 of thedrawings, several'of my line-severing devices are towed by a ship through the water in the direction of the arrow by means of a, sweep line, 1 that extends laterally-at an angle from the stern of the ship. The sweep line is held at the desired angle and depth by means that form no part of-this invention. Each severing device has two major parts; a frame 2 and a vane or fin 3 that keeps the frame more or lesshorizontal and projecting ahead of the-sweep line. The end of the fin adjacent the line is bifurcated and detachably zontal regardless of the twisting of the line. Thefin is heldin placeby means of the usual positioning collars 6- clamped on the sweep line and providedat their inner ends with tapered bosses 7 that project into sockets in the These bosses and sockets serve as bearings that facilitate rotation of the fin on the sweep line.

The rear end of frame 2 projects between yokes 4 and 5 and likewise is detachably mounted on the sweep line and rotatable relative to it. The sides of this end of the frame are provided with sockets that receive circular bosses 8 on the adjoining ends of the yokes to provide bearings for rotation of-the frame relative to the fin. Normally, however, the frame and fin are locked together as a unit by means of a locking pin 9 carried by the frame and projecting into an opening in yoke 4. Although the frame may be disposed at right anglesto the sweep line, it is preferred to have. it projectstraig-ht ahead in the direction it is towed through the water.

Removably mounted in a space provided in the side of the frame facing the ship is a barrel 11 in which a punch or wedge 12 is slidably-mounted. The innerend of the wedge is in the form of a piston while the opposite in the tube.

axis of the wedge and centered relative to it. The entrance to the recess is too narrow to receive the link in any position except edgewise, and the front of yoke 5 is provided Witha ridge having a narow fiat surface 16 (Fig. 6) for engaging the central portion of the link and guiding it edgewise into the recess. The sides of the ridge are of such contour as to permit the two links 17 at the opposite ends of link to lie at right angles to the center link while the latter is sliding into the recess.

To drive the wedge into engagement with the chain the wedge preferably is explosively actuated, and therefore the inner end of the barrel is provided with an opening in which an explosive cartridge 20 is inserted with one end a short distance from the inner end of the wedge. The cartridge is exploded by a firing pin 21 slidably mounted in the front end of the frame. In accordance with this invention the central portion of this pin is enlarged to form a collar between which and the frame a coil spring 22 is compressed to normally hold the pin retracted. The small area in which this spring is located is connected to the outside of the frame by avent 23. The opposite side of the firing pin collar is connected by a passage 24 through the frame with the inside of a tube 26 rigidly mounted in a longitudinal recess in the side of the frame by means of cross pieces 27 screwed to the frame, as shown in Figs. 2 and 3. A short distance from the closed front end of the tube the side of the tube is provided with an opening 28 that admits sea water to the tube and passage when the device is submerged. The water pressure will force any air trapped in the passage past the firing pin and out of vent 23. When it is time to fire the cartridge the water in passage 24 is suddenly put under sufi'icient pressure to drive the pin against the cartridge cap. This is done by means of a plunger 30 slidably mounted in the tube and normally held in retracted position, with its front end behind the side wall opening 28 of the tube, by a trigger pin 31 slidably mounted in the frame with its inner end extending through a hole in the tube and into a peripheral groove 32 in the rear end of the plunger. This pin is pressed inwardly by a coil spring 33 encircling it inside the frame. When the trigger pin is withdrawn from engagement with the plunger, the latter is shot forward in the tube by a long coil spring 34 disposed in the hollow plunger and compressed between it and a fixed plug 35 The shear pin 14 in the wedge compels the explosion to build up considerable pressure before the pin is sheared off and the Wedge shot out of the barrel with great force.

The trigger pin 31 is pulled out of contact with the plunger by means of a U-shape trigger 37 that straddles the frame to which it is pivotally connected by screws 38. The projecting end of the trigger pin is reduced in size and extends through an inwardly tapered slot 36 in one side of the trigger, while the extreme end portion of the trigger pin is tapered toward the trigger and engages the chamfered sides of the slot as shown in Fig. 5. When the center link 15 (Fig. 7) enters severing recess 13 the two end links 17 engage the ends of the trigger projecting to the right of pivot screws 38 at the opposite ends of the recess as shown in Figs. 2 and 5, and the forward pull of the device on the chain causes the chain to bend and links 17 to swing back the trigger on its pivots 38, thereby rotating the trigger in a clockwise direction as viewed in Figs. 2 and 5. This causes the tapered slot 36 to exert on the trigger pin a wedging action which moves it outwardly of the frame and thereby releases plunger 30. It will be seen that before this device is placed in the water the accidental release of the plunger will not cause the firing pin to discharge the cartridge because there will be no water behind the firing pin to move it.

Except in the case of small chains the wedge does not sever the chain by cutting link 15, but rather by breaking it. Thus, the tapered or operative end of the wedge is narrow enough in one direction to enter the space be- 4 tween the sides of the link, but wide enough in the other direction to strike the adjacent ends of links 17 and wedge them apart as it moves between them. This action, combined with the tension on the chain, pulls the center link 15 apart, usually at points about midway between its ends. The shock of the impact of the wedge also helps break the chain because it often is found that the two links 17 are broken apart. To prevent only one side of link 15 from being pulled apart and the other side merely stretched and bent, the recess has side walls shaped to engage both sides of the link and thus compel the end links 17 to exert substantially uniform tension on both sides of the center link.

At substantially the same moment that the trigger releases plunger 30 it also pulls-locking pin 9 out of yoke 4 so that the frame can rotate on the sweep line independently of the fin. This is done, as shown in Fig. 2, by means of a screw 41 projecting from the back part of the trigger through a slot 42 in tube 26 and into a hole 43 in the locking pin. Movement of the trigger by the chain causes this screw to be moved forward and thereby to pull the locking pin out of the yoke 4 against the resistance of a coil spring 44 compressed between the pin and plug 35. Gravity, or the force of the water, will immediately swing the frame back around the sweep line so that it will not catch onto the next mine line that is encountered by the sweep line and. prevent it from reaching and being severed by a similar undischarged device further along the sweep line.

In case a cable instead of a chain enters severing recess 13 it will move the trigger and discharge the cartridge in the same way as a chain. However, the wedge will act as a knife and cut the cable in two against an anvil 46 (Figs. 2 and 4) that is mounted opposite to the wedge in a central recess in the back wall of the severing recess 13. To prevent the cable from passing across the anvil and becoming caught in the back of the severing recess where it would not actuate the trigger, the sides of the trigger project part way across the opposite ends of the recess as shown in Figs. 2 and 5. These projections do not interfere with a mine chain because link 15 is disposed between them while links 17 do not extend into the back part of the severing recess.

After the cartridge has been discharged it can be replaced by a new one merely by removing barrel 11 from the frame. The plunger 30 can be cocked by inserting a screw driver or the like in the tube opening 28 and pushing the plunger back in the tube until the trigger pin 31 snaps into plunger recess 32.

According to theprovisions of the patent statutes, I have explained the principle and mode of operation of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. A mine chain breaker for attachment to a sweep line, comprising a movable wedge, means adjacent the operative end of the wedge for catching a mine chain link and holding it in a plane substantially perpendicular to the direction of movement of the wedge, and means for driving the wedge between and against the ends of the two chain links connected to said caught link to force them in opposite directions and thereby pull the center link apart.

2. A mine chain breaker for attachment to a sweep line, comprising a movable wedge, means adjacent the operative end of the wedge for catching a mine chain link and holding it in a plane substantially perpendicular to the direction of movement of the wedge, means adapted to receive an explosive charge adjacent the opposite end of the wedge, and means for exploding the charge to drive the wedge between and against the ends of the two chain links connected to said caught link to force them apart.

in opposite directions and thereby pull the center 3. A mine chain breaker for attachment to a sweep line, comprising a movable wedge, means adjacent the "operative end of the wedge for catching amine chain link and "holding it in a plane substantially perpendicular to the direction of movement of the wedge, and means set in operation by said chain for driving the wedge between and against the, ends of the two chain links connected to said caught link to force them in opposite directions and thereby pull the center link apart.

4. A mine chain breaker for attachment to a sweep line, comprising a movable wedge, means adjacent the operative end of the wedge for catching a mine chain link and holding it in a plane substantially perpendicular to the direction of movement of the wedge, means adapted to receive an explosive charge adjacent the opposite end of. the wedge, a firing pin for-said charge, and means operable by said chain for actuating the firing pin to explode the charge in order to drive the wedge between and against the ends of the two chain links connected to said caught link to force them in opposite directions and thereby pull the center link apart.

5. A mine chain breaker for attachment to a sweep line, comprising a movable wedge, means adjacent the operative end of the wedge for catching a mine chain link and holding it in a plane substantially perpendicular to the direction of movement of the wedge, means adapted to receive an explosive charge adjacent the opposite end of the wedge, a firing pin for said charge, and means operable by said chain for exerting hydraulic pressure on the firing pin to explode the charge in order to drive the wedge between and against the ends of the two chain links connected to said caught link to force them in opposite directions and thereby pull the center link apart.

6. A mine chain breaker for attachment to a sweep line, comprising a movable wedge, means adjacent the operative end of the wedge for catching a mine chain link and holding it in a plane substantially perpendicular to the direction of movement of the wedge, means for driving the wedge between and against the ends of the two chain links connected to said caught link to force them in opposite directions and thereby pull the center link apart, and means operable when the chain is broken to release said chain-catching means from operative position whereby the breaker offers no obstruction to the next mine chain engaged by the sweep line.

7. A combination mine chain breaker and mine cable cutter for attachment to a sweep line, comprising a movable wedge, means adjacent the operative end of the wedge adapted to catch a mine chain link and hold it in a plane substantially perpendicular to the direction of movement of the wedge, means adapted to drive the wedge between and against the ends of the two chain links connected to said caught link to force them in opposite directions and thereby pull the center link apart, and an anvil against which the wedge cuts a mine cable in case such a cable is caught instead of a chain.

8. A mine chain breaker for attachment to a sweep line, comprising a movable wedge, means adjacent the operative end of the wedge for catching a mine chain link and holding it in a plane substantially perpendicular to the direction of movement of the wedge, means for engaging the central portion of said link and guiding it edgewise to said catching means, and means for driving the wedge between and against the ends of the two chain links connected to said caught link to force them in opposite directions and thereby pull the center link apart, said holding means substantially engaging the outer surfaces of the opposite sides of the center link as it is pulled apart.

9. A mine chain breaker for attachment to a sweep line, comprising a frame, a longitudinally movable wedge carried by the frame, said frame being provided with a restricted recess adjacent the operative end of the wedge ior receiving a mine chain link flatwise, the walls of the recess being shaped'to hold-the-link in a plane substantially perpendicular to the direction of movement of the wedge, and means for driving the wedge between and agains tthe endsof-the two chain links connected to said caughtli-nkto force them in opposite directions and-thereby pull-the center link apart. v

10. A mine chain breaker for attachment to-a sweep line; comprisingaframe, a longitudinally movable wedge carried by the frame, said frame being provided with a restricted recess adjacent the operative end'of the'wedge for receiving a mine chain link fiatwise, the walls of the recess being shaped to hold the link in a plane-substantially perpendicular tothe direction of movement of the wedge, and means fordriving the wedge between and against the ends of the: two chain linksconnected to said caught link to force them in opposite-directions and thereby pull the center link apart, said recess having front and back walls that engage the opposite sidesoflthe center link. i 1

ll. A. mine chain breaker for attachment to a sweep line, comprising a frame, a longitudinally movable wedge carried by the frame, said frame being provided with a recess adjacent the operative end of the wedge for receiving a mine chain link, the walls of the recess being shaped to hold the link in a plane substantially perpendicular to the direction of movement of the wedge, and

means for driving the wedge between and against the.

ends of the two chain links connected to said caught link to force them in opposite directions and thereby pull the center link apart, the wall of the recess opposite the wedge being recessed for receiving and holding a mine cable for cutting by the wedge.

12. A mine chain breaker for attachment to a sweep line, comprising a frame, a longitudinally movable wedge carried by the frame, said frame being provided with a recess adjacent the operative end of the wedge for receiving a mine chain link, the walls of the recess being shaped to hold the link in a plane substantially perpendicular to the direction of movement of the wedge, means for driving the wedge between and against the ends of the two chain links connected to said caught link to force them in opposite directions and thereby pull the center link apart, the wall of the recess opposite the wedge being recessed for receiving and holding a mine cable for cutting by the wedge, and means at the side of the frame for guiding the cable into position.

13. A device for attachment to a sweep line for severinga mine-anchoring line, comprising a movable severing member, means adjacent the operative end of said member for catching a mine line and holding it in position for severing, means adapted to receive an explosive charge adjacent the opposite end of the severing member, a firing pin for exploding the charge to actuate the severing member, spring actuated means for forcing water under pressure against the firing pin to actuate it, and means operable by said mine line for releasing said spring actuated means.

14. Adevice for attachment to a sweep line for severing a mine-anchoring line, comprising a movable severing member, means adjacent the operative end of said member for catching a mine line and holding it in position for severing, means adapted to receive an explosive charge adjacent the opposite end of the severing member, a firing pin for exploding the charge to actuate the severing member, a passage communicating at one end with the firing pin and open at the other end, normally retracted spring pressed means adjacent the open end of said passage, and means for releasing said spring pressed means whereby sea water in said passage is forced against 7 frame tosaid first-mentioned means, mine line severing means carried by the frame, and means actuated when a mineline is severed for unlocking said locking means to release the frame from said first mentioned meanswhereby the frame is allowed to rotate around the sweep line independently of said first-mentioned means and swing back out of mine line obstructing position.

16; A device for severing mine-anchoring lines, com

mounted at one endon a sweep line, frame-positioning means adapted to be rotatably. mounted at its front end on the sweep line, means for locking the frame to said positioning means, mine'line severing means carried by the frame, and means. for unlocking the frame from said positioning means when a mine line is severed whereby the frame is allowed to rotate around the sweep line relative to andindependent of said positioning means.

17. A device for severing mine-anchoring lines, com- 7 prising a frame adapted to be rotatably mounted at one endon asweep line, frame-positioning means adapted prising a frame adaptedto engage andto be rotatably to be rotatablymounted atits front, end on the sweep line. and provided with a recess, a locking member carried by the frame and normally projecting into said recess-for locking the frameto said positioning means,;mine: line severing means carried byithe. frame, and means for withdrawing said locking member from said recess when amine line is severed whereby the frame is allowed to rotate on the sweep line relative to said positioning means.

References Cited in thefiie of this patent UNITED STATES PATENTS Germany: Dec. 24, 1919 

